typescript
Typescript is a typed superset of Javascript that transpiles (is converted) to plain Javascript.
Install
- npm install -g typescript
 
Compile
- tsc helloworld.ts
 
kate
https://github.com/PrettyFlower/KateTypeScriptSyntaxHighlighting
wget https://github.com/PrettyFlower/KateTypeScriptSyntaxHighlighting/raw/master/typescript.xml cp typescript.xml /usr/share/apps/katepart/syntax/typescript.xml
With let keyword added
   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE language SYSTEM "language.dtd">
   3 <language name="TypeScript" section="Scripts" extensions="*.ts;"
   4         indenter="cstyle" author="PrettyFlower (abigchode@gmail.com)">
   5 <highlighting>
   6     <list name="keywords">
   7         <item> if </item>
   8         <item> else </item>
   9         <item> for </item>
  10         <item> in </item>
  11         <item> while </item>
  12         <item> do </item>
  13         <item> continue </item>
  14         <item> break </item>
  15         <item> with </item>
  16         <item> try </item>
  17         <item> catch </item>
  18         <item> finally </item>
  19         <item> switch </item>
  20         <item> case </item>
  21         <item> new </item>
  22         <item> var </item>
  23         <item> function </item>
  24         <item> return </item>
  25         <item> delete </item>
  26         <item> true </item>
  27         <item> false </item>
  28         <item> void </item>
  29         <item> throw </item>
  30         <item> typeof </item>
  31         <item> const </item>
  32         <item> default </item>
  33         <item> this </item>
  34         <item> null </item>
  35         <item> undefined </item>
  36         
  37         <item> class </item>
  38         <item> export </item>
  39         <item> declare </item>
  40         <item> module </item>
  41         <item> import </item>
  42         <item> static </item>
  43         <item> interface </item>
  44         <item> implements </item>
  45         <item> constructor </item>
  46         <item> public </item>
  47         <item> private </item>
  48         <item> string </item>
  49         <item> number </item>
  50         <item> bool </item>
  51         <item> any </item>
  52         <item> extends </item>
  53         <item> let </item>
  54     </list>
  55     
  56     <contexts>
  57         <context attribute="Normal Text" lineEndContext="#stay" name="Normal">
  58             <DetectSpaces/>
  59             <keyword attribute="Keyword" context="#stay" String="keywords"/>
  60             <DetectChar attribute="String" context="String" char="""/>
  61             <DetectChar attribute="String Char" context="String 1" char="'"/>
  62             <StringDetect attribute="Reference" context="Reference" String="///" />
  63             <Detect2Chars attribute="Comment" context="Comment" char="/" char1="/"/>
  64             <Detect2Chars attribute="Comment" context="Multi/inline Comment" char="/" char1="*" beginRegion="Comment"/>
  65             <DetectIdentifier/>
  66         </context>
  67         
  68         <context attribute="String" lineEndContext="#pop" name="String">
  69             <DetectIdentifier/>
  70             <HlCStringChar attribute="String Char" context="#stay"/>
  71             <LineContinue attribute="String" context="#stay"/>
  72             <DetectChar attribute="String" context="#pop" char="""/>
  73         </context>
  74         
  75         <context attribute="String Char" lineEndContext="#pop" name="String 1">
  76             <DetectIdentifier/>
  77             <HlCStringChar attribute="String Char" context="#stay"/>
  78             <LineContinue attribute="String" context="#stay"/>
  79             <DetectChar attribute="String Char" context="#pop" char="'"/>
  80         </context>
  81 
  82         <context attribute="Comment" lineEndContext="#pop" name="Comment">
  83             <DetectSpaces />
  84             <IncludeRules context="##Alerts" />
  85             <DetectIdentifier />
  86         </context>
  87         
  88         <context attribute="Comment" lineEndContext="#stay" name="Multi/inline Comment">
  89             <IncludeRules context="##Alerts" />
  90             <Detect2Chars attribute="Comment" context="#pop" char="*" char1="/" endRegion="Comment"/>
  91         </context>
  92         
  93         <context attribute="Reference" lineEndContext="#pop" name="Reference">
  94             <DetectChar attribute="ReferenceBracket" context="#stay" char="<"/>
  95             <DetectChar attribute="ReferenceBracket" context="#stay" char=">"/>
  96             <DetectChar attribute="ReferenceFile" context="ReferenceFile" char="""/>
  97             <DetectChar attribute="ReferenceFile" context="ReferenceFile 1" char="'"/>
  98         </context>
  99         
 100         <context attribute="ReferenceFile" lineEndContext="#pop" name="ReferenceFile">
 101             <DetectIdentifier/>
 102             <HlCStringChar attribute="ReferenceFile" context="#stay"/>
 103             <LineContinue attribute="ReferenceFile" context="#stay"/>
 104             <DetectChar attribute="ReferenceFile" context="#pop" char="""/>
 105         </context>
 106         
 107         <context attribute="ReferenceFile" lineEndContext="#pop" name="ReferenceFile 1">
 108             <DetectIdentifier/>
 109             <HlCStringChar attribute="ReferenceFile" context="#stay"/>
 110             <LineContinue attribute="ReferenceFile" context="#stay"/>
 111             <DetectChar attribute="ReferenceFile" context="#pop" char="'"/>
 112         </context>
 113     </contexts>
 114     <itemDatas>
 115         <itemData name="Normal Text" defStyleNum="dsNormal"/>
 116         <itemData name="Keyword" defStyleNum="dsNormal" color="#00f"/>
 117         <itemData name="Char" defStyleNum="dsChar"/>
 118         <itemData name="String" defStyleNum="dsString" color="#a31515"/>
 119         <itemData name="String Char" defStyleNum="dsString" color="#a31515"/>
 120         <itemData name="Comment" defStyleNum="dsNormal" italic="true" color="#080"/>
 121         <itemData name="Reference" defStyleNum="dsNormal" color="#aeb9ae"/>
 122         <itemData name="ReferenceBracket" defStyleNum="dsNormal" color="#708870" bold="true"/>
 123         <itemData name="ReferenceFile" defStyleNum="dsNormal" color="#2c51cc"/>
 124     </itemDatas>
 125 </highlighting>
 126 <general>
 127     <comments>
 128         <comment name="singleLine" start="//" />
 129         <comment name="multiLine" start="/*" end="*/" />
 130     </comments>
 131     <keywords casesensitive="1"/>
 132 </general>
 133 </language>
Sample code typescript for browser
greeter.html
lib.ts
Any declaration (such as a variable, function, class, type alias, or interface) can be exported by adding the export keyword.
export function getText(){
    return "text";
}
greeter.ts
- import {xyz} from "module";
 
import {getText} from "./lib";
interface Person {
    firstName: string;
    lastName: string;
}
function greeterPerson(p:Person) {
    return "Hello GP, " + p.firstName + ' ' + p.lastName + ' ' + getText() ;
}
function greeter(person:string) {
    return "Hello, " + person;
}
var user = "XPTO User";
//document.body.innerHTML = greeter(user);
document.body.innerHTML = greeterPerson( 
{firstName:"First",lastName:"Last"}  
);
tsconfig.json
webpack.config.js
build.sh
ReactJS + typescript example
https://reactjs.org/ A JavaScript library for building user interfaces. Build encapsulated components that manage their own state, then compose them to make complex UIs.
https://reactjs.org/docs/thinking-in-react.html
Structure
webpack.config.js
tsconfig.json
lib.ts
function getText() {
    return "text";
}
interface Person {
    firstName: string;
    lastName: string;
}
function greeterPerson(p: Person) {
    return "Hello GP, " + p.firstName + ' ' + p.lastName + ' ' + getText();
}
function greeter(person: string) {
    return "Hello, " + person;
}
interface HumanInterface {
    name: string;
    getName(): void;
}
class Human implements HumanInterface {
    name: string;
    constructor(name: string) {
        this.name = name;
    }
    getName() {
        return "My name is " + this.name;
    }
}
class PubSub {
    callbacks: Function[];
    constructor() {
        this.callbacks = [];
    }
    addListener(fn: Function): void {
        this.callbacks.push(fn);
    }
    notify(message: string): void {
        this.callbacks.forEach((fn) => {
            fn(message);
        });
    }
}
let pubSub = new PubSub();
export { greeter, greeterPerson, Human, HumanInterface, Person, getText, PubSub, pubSub }
greeter.html
package.json
App.tsx
import React, { ReactChild } from 'react';
import { Person, greeterPerson, Human, HumanInterface } from './lib';
import NameHolder from './NameHolder';
import { pubSub } from './lib';
interface MyState {
    currDate: string;
    greetings: string;
    human: HumanInterface;
}
function createMyState(currDate: string, greetings: string, human: HumanInterface): MyState {
    return { currDate: currDate, greetings: greetings, human: human };
}
interface MyProps {
    prop: string;
}
export default class App extends React.Component<MyProps, MyState> {
    text: string;
    timerID: number;
    constructor(props: MyProps) {
        super(props);
        this.text = this.props.prop;
        this.state = createMyState("waiting for date", "waiting for greetings", null); // init with MyState format          
    }
    public static createHuman(name: string): HumanInterface {
        return new Human(name);
    }
    public tickHandler() {
        let cd = new Date().toString();
        let greetings = greeterPerson({ firstName: "first", lastName: "last" });
        let human: HumanInterface = App.createHuman("JohnDoe");
        this.setState(createMyState(cd, greetings, human));
    }
    componentDidMount() {
        // called after the 1st render !
        console.log("First render");
        this.timerID = setInterval(this.tickHandler.bind(this), 1000);
    }
    componentWillUnmount() {
        // component will be destroyed
        console.log("Will be destroyed soon");
        clearInterval(this.timerID);
    }
    public render() {
        // do not call set state in render !
        return (
            <div>
                <p>Hello World!!! -- {this.text} -- {this.state.greetings}</p>
                <p>Human {this.state.human != null ? this.state.human.getName() : ""} {this.state.currDate} </p>
                <p> <NameHolder attr="holding..." />  </p>
                <p> <NameHolder attr={this.state.currDate} /> </p>
                <div onClick={() => { this.clickHandler(); }} > {this.props.children} </div>
            </div>
        );
    }
    public clickHandler() {
        console.log("clicked. # children " + React.Children.count(this.props.children));
        React.Children.forEach(this.props.children, (argx: any) => {
            if (argx.hasOwnProperty("props")) {
                console.log("props property found");
                pubSub.notify("message from outer space !");
            }
            console.log(JSON.stringify(argx));
        });
    }
}
greeter.tsx
import React from 'react';
import ReactDOM from 'react-dom';
import {getText} from "./lib";
import App from './App'; // uses App.tsx
import NameHolder from './NameHolder'; 
console.log("Entry point");
let appContainer =  document.getElementById('app') ;
let markup = <App prop="Other text inside the page"> <NameHolder attr="NameHolder child inside App "/> </App>;
ReactDOM.render( markup , appContainer);
NameHolder.tsx
import React from 'react';
import { pubSub } from './lib';
// Component properties (XML attributes)
interface NameHolderProperties {
    attr: string;
}
interface NameHolderState {
    attr: string;
}
// properties and state 
export default class NameHolder extends React.Component<NameHolderProperties, NameHolderState> {
    constructor(props: NameHolderProperties) {
        super(props); // populates the this.props         
        this.state = { attr: this.props.attr };
        pubSub.addListener(this.onMessage);
    }
    public render() {
        return <span>!!!{this.state.attr}!!!</span>;
    }
    public onMessage(message: string): void {
        console.log(this.state.attr + " receiVed " + message);
    }
}
build.sh
Constants
export class Constants {
    static readonly CONST_A = "constA";
    static readonly CONST_B = "constB";
}
Console app hello world
   1 cd /tmp
   2 mkdir bar 
   3 cd bar
   4 npm init 
   5 echo '{ "compilerOptions": {  "target": "es5", "sourceMap": true } }' > tsconfig.json 
   6 npm install typescript ts-node
   7 npm install @types/node
   8 echo -e '#!/usr/bin/env node\nconsole.log("Hello world!");' > index.ts
   9 ./node_modules/ts-node/dist/bin.js index.ts
Promise
new Promise<boolean>(  (resolve,reject)=>{
  resolve(true);
  reject('Error occured');
} );
//resolve
.then( (value)=>{} )
// reject
.catch( (value)=>{} )